This invention is directed generally to a connector for flexible coaxial cable and, in particular, to an electrical connector for terminating the end of flexible coaxial cable that is relatively small in size and does not require any crimping.
Coaxial connectors have taken many forms in the prior art as exemplified by U.S. Pat. No. 4,408,821 (Forney, Jr.) which is directed to a connector for semi-rigid coaxial cable. The connector for semi-rigid coaxial cable of Forney, Jr. is directed to a connector that does not require crimping. It uses a grip ring having multiple spline fingers extending therefrom and grooves on its inner surface, and a bored tubular shell member having a contoured internal diameter to accept the cable and the grip ring. When the grip ring and cable are inserted into the tubular body, the spline fingers resiliently deflect inwardly along the shell member contour, and embed into the outer semi-rigid cable sheath. This connector system can not provide termination for flexible cables because they do not include a semi-rigid sheath for the spline fingers to embed into.
U.S. Pat. No. 5,186,655 (Glenday, et al.) is directed to an RF connector. This connector locks in place by having a sleeve that is insertable between the outer conductor of a coaxial cable and the inner dielectric, such that the jacket and the outer conductor are deformed. After the sleeve is inserted, a coupling nut is then moved into place and frictionally engages the sleeve. This invention suffers deficiencies in the manner that the jacket electrically connects with the outer conductor, and the way that the coupling nut is coupled to the sleeve. The Glenday, et al. invention can not provide electrical performance for microwave frequencies because the method of deforming the plastic jacket on the outer conductor does not provide sufficient electrical contact at microwave frequencies. Therefore, this connector can not be used for microwave transmission, and is useful only for frequencies up to a few hundred MHz (CATV).
In today's electronic marketplace, microwave communication systems (i.e., cellular systems and point-to-point microwave radios) and the relative packaging of these systems require miniaturization, and dense packaging of electronic elements within small cases. Accordingly, when a system is designed, the designers often desire flexible coaxial cable in order to easily manipulate the cable, and further require miniaturization of the connector elements therefor.
The first attempts at low profile connectors for flexible coaxial cable included right angle connectors which still required crimping. While decreasing the profile of the connector to some extent, this still required a long section of rigid crimped connector, and did not substantially help designers in saving space. Furthermore, the electrical performance of right angle connectors is inferior and requires increased amplification due to VSWR and insertion loss.
Accordingly, it is desirable to provide a connector for flexible coaxial cable that provides a low profile and does not require the usual crimp attachment which increases the profile and limits the design choices. Furthermore, it is required that the connector be able to function at microwave frequencies from DC-24 GHz.